Tuna are large, oceanic fish that migrate with the seasons, some making long journeys across oceans. Able to tolerate both warm and cool temperatures, bluefin tuna range throughout the entire north Atlantic and adjacent seas, (primarily the Mediterranean Sea) and survive as deep as 1000m. Despite this, a recent analysis of present vs. historical ranges concluded that the range that Atlantic bluefin tuna covers has reduced by 46% since 1960 - more than any other pelagic species. Spawning occurs from April to June in the Gulf of Mexico and June to August in the Mediterranean. Atlantic bluefin grow slowly compared with other tunas and billfish, taking 5 years to reach maturity. They start out no bigger than an eyelash and can grow to the size of a small car in less than 10 years! They can live for 40 years, reaching 2.7m and weighing 400kg.